Erkki Hartikainen (1942–): is a Finnish atheist activist. He is the chairman of the Atheist Association of Finland (Suomen Ateistiyhdistys) and former chairman of the Union of Freethinkers of Finland (Vapaa-ajattelijoiden liitto), the biggest atheistic association in Finland.[22]

Charles Lee Smith (1887–1964): an atheist activist in the United States and an editor of the Truth Seeker until his death. He also founded the American Association for the Advancement of Atheism. Smith was arrested twice in 1928 for selling atheist literature and for blasphemy. Since he refused to swear an oath to God on the Bible, he was not allowed to testify in his own defense.[45]

Barbara Smoker (1923–): British humanist activist and freethought advocate. Wrote the book Freethoughts: Atheism, Secularism, Humanism – Selected Egotistically from The Freethinker.[46]

Henry Stephens Salt (1851–1939): English writer and campaigner for social reform in the fields of prisons, schools, economic institutions and the treatment of animals, a noted anti-vivisectionist and pacifist, and a literary critic, biographer, classical scholar and naturalist, and the man who introduced Mahatma Gandhi to the influential works of Henry David Thoreau.[61]